276 PROCEEDINGS OF SECTION C. 



Between the Narrabeen Shales and the topmost beds of the 

 productive Coal-measures there intervenes a considerable thick- 

 ness of strata, at present unnamed, which, for convenience in this 

 paper, will be termed the Estheria ShaJfs. The cupriferous tuffs 

 about to be described form an intercalated stratum in the latter. 



Prospecting operations by means of the diamond drill, have 

 lately proved that these tuffs aresomewliat extensively developed, 

 and they are now known to extend from B villi on the south to at 

 least as far as Holt-Sutherland on the north, a distance of seven- 

 teen miles. 



The stvidy of the occurrence of this shale, as will be shewn in 

 the sequel, is not only of great scientific interest, but may prove 

 of considerable economic importance, as affecting conclusions as 

 to the probable depth of the Coal-measures in the improved area 

 between Parramatta and Sydney. 



Mention by Previous Authors. 



As far as the author is aware the only description of these 

 shales published hitherto, is the one given by himself in a paper 

 read before the " Geological Society of Australasia," on May 13, 

 1887.* The only possible previous allusion to these shales was 

 made by Mr. Bensusan in 1 878.1 In the reference given below 

 it is recorded that Mr. Bensusan laid on the table at a meeting 

 of the Royal Society " a specimen of indurated clay from the 

 boring at Newington from a depth of 1150 feet, showing a nodule 

 of quartz containing metallic copper, which had been cut through 

 by tlie diamond drill horer. The clay is similar to that found at 

 Bulli 700 feet above the coal seam." The expression " nodule of 

 quartz " here seems to infer that the stone in which the copper 

 occurred was a deiived fiagment, and does not imply that the 

 native copper was "in situ " in the shale. 



The first person, as far as the author is aware, who unques- 

 tionably observed native copper " in situ " in these shales, was 

 Mr. John Waterhouse, M.A., Head Ma.ster of the High School, 

 "West Maitland, who assures the author that he noticed scales of 

 metallic copper " in situ " in the shale core from the Newington 

 bore, in the year 1878. No description of this however was given 

 by him at the time. 



Mr. W. A. Dixon, F.I.C., F.C.S., informs me that some years 

 ago a sample of copper-bearing shale was sent to him for as&ay 

 from near Bulli, but he did not puVjlish any description of it. 



My colleague, Mr. William Anderson, was the first to discover 

 the tuft'aceous origin of the cupriferous shale, its resemblance to 



* Trans. Geol. Soc. Australasia, I., Part HI., pp. 82-89. 

 t Journ. Roy. Soc. N. S. Wales, 1878, XII., p. 254. 



